step(ps,ci,tm(s,[ctxm(alpha_2_3_,ps,ip, (ip,ps), (ip,ps)),ctxm(alpha_2_3_,ci,ip, (ip,ci), (ip,ci))],pri(pc,[ctxm(alpha_2_3_,dot,s,i_s,c_s),ctxm(alpha_2_3_,u,bsn,i_bsn,i_bsn),ctxm(alpha_2_3_,ci,dom, (dom,ci), (dom,ci))]))).
